package com.flow.tools;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;

/**
 * 验证码
 * 
 * @author wang
 * @version 2015-12-5
 */
public class PrintCode {

	/**
	 * 验证码图片中可以出现的字符集，可根据需要修改
	 */
	private char mapTable[] = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i',
			'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
			'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8',
			'9' };

	/**
	 * 图片宽度
	 */
	private int width = 80;

	/**
	 * 图片高度
	 */
	private int height = 30;

	/**
	 * 生成颜色 
	 */
	private Color getRandColor() {
		
		int fc = 122; 
		int bc = 200;
		Random random = new Random();
		if (fc > 255)
			fc = 255;
		if (bc > 255)
			bc = 255;
		int r = fc + random.nextInt(bc - fc);
		int g = fc + random.nextInt(bc - fc);
		int b = fc + random.nextInt(bc - fc);
		
		return new Color(r, g, b);
	}

	/**
	 * 功能:生成彩色验证码图片 参数width为生成图片的宽度,参数height为生成图片的高度,参数os为页面的输出流
	 */
	public String getCodePic(OutputStream os) {

		// 取随机产生的认证码
		String strEnsure = "";

		try {

			BufferedImage image = new BufferedImage(width, height,
					BufferedImage.TYPE_INT_RGB);
			// 获取图形上下文
			Graphics g = image.getGraphics();
			// 设定背景色
			g.setColor(getRandColor());
			g.fillRect(0, 0, width, height);
			// 画边框
			g.drawRect(0, 0, width - 1, height - 1);
			// 4代表4位验证码,如果要生成更多位的认证码,则加大数值
			for (int i = 0; i < 6; ++i) {
				strEnsure += mapTable[(int) (mapTable.length * Math.random())];
			}
			// 　　将认证码显示到图像中,如果要生成更多位的认证码,增加drawString语句
			g.setColor(Color.black);
			g.setFont(new Font("Atlantic Inline", Font.PLAIN, 18));
			String str = strEnsure.substring(0, 1);
			g.drawString(str, 8, 20);
			str = strEnsure.substring(1, 2);
			g.drawString(str, 15, 15);
			str = strEnsure.substring(2, 3);
			g.drawString(str, 25, 18);
			str = strEnsure.substring(3, 4);
			g.drawString(str, 35, 23);
			str = strEnsure.substring(4, 5);
			g.drawString(str, 45, 16);
			str = strEnsure.substring(5, 6);
			g.drawString(str, 60, 20);
			// 随机产生10个干扰点
			Random rand = new Random();
			for (int i = 0; i < 50; i++) {
				int x = rand.nextInt(width);
				int y = rand.nextInt(height);
				g.drawOval(x, y, 1, 1);
			}
			// 释放图形上下文
			g.dispose();

			// 输出图像到页面
			ImageIO.write(image, "JPEG", os);
		} catch (IOException e) {
			return "";
		}

		return strEnsure;
	}

	public int getWidth() {

		return width;
	}

	public void setWidth(int width) {

		if (width <= 0)
			width = 60;
		else
			this.width = width;
	}

	public int getHeight() {

		return height;
	}

	public void setHeight(int height) {

		if (height <= 0)
			height = 20;
		else
			this.height = height;
	}
}
